Comparative lens

Problems: compare 
Tags: superposition 

A comparative lens can be used to compare two maps, typically for before / after comparisons, with a possibility to exchange the position of each map (above / under). See also:

Examples

Cities: Before and After series

Other comparison of US cities are available in the Cities: Before and After series by the Smithsonian Mag.

Banlieue is Beautiful Project

Several comparative lenses can be added separately or together on this map, which illustrates the presence of various artistic entities in conjunction with past and future urban projects.